1. Field of the Innovation
The present innovation relates generally to the fields of biophysics, bioelectromechanics, tissue regeneration, tissue culture, and neurophysiology. More specifically, the present innovation relates to the use of an electromagnetic field, and preferably, a time-varying magnetic field, for modifying, potentiating or controlling the growth and specific genetic expression of biological cells and tissue, such as mammalian tissue. More specifically, the present innovation relates to the use of a noninvasive method and apparatus comprising relatively low frequency magnetic fields for modifying the genetic regulation of mammalian chondrocytes, osteoblasts, osteocytes, osteoclasts, nucleus pulposus, associated tissue, or any combination.
2. Background and Related Art
Cartilage
Cartilage is a type of dense connective tissue existing within many joints. It is composed of specialized cells called chondrocytes that produce a large amount of extracellular or cartilaginous matrix comprised of actin and collagen fibers, proteoglycans, glycosaminoglycans, and elastin fibers. Chondrocytes are the only cells found in cartilage. Cartilage is classified in three types, elastic cartilage, hyaline cartilage, and fibrocartilage. Cartilage is found in many areas in a mammalian body, including the articular surface of the bones, the rib cage, the ear, the nose, the bronchial tubes and the intervertebral discs. Its mechanical properties are intermediate between bone and dense connective tissue like tendon. (Cartilage, 2010)
Unlike other connective tissues, cartilage does not contain blood vessels or is referred to as avascular. The chondrocytes are fed by diffusion, helped by the pumping action generated by compression of the articular cartilage or flexion of the elastic cartilage. Thus, compared to other connective tissues, cartilage grows and repairs more slowly. (Cartilage, 2010)
There are several diseases which can affect the cartilage. Chondrodystrophies are a group of diseases characterized by disturbance of growth and subsequent ossification of cartilage. Osteoarthritis (OA) is a common disease affecting cartilage. Osteoarthritis, also known as a degenerative joint disease, is a group of mechanical abnormalities involving degradation of joints, including articular cartilage and subchondral bone. The cartilage covering bones (articular cartilage) is thinned, eventually completely worn out, resulting in a “bone against bone” joint, reduced motion, and pain. Osteoarthritis is very common, affects the joints exposed to high stress, and is therefore considered the result of “wear and tear” rather than a true disease. The usual symptoms are stiffness, limitation of motion, and pain. Osteoarthritis is the most common form of arthritis, and prevalence rates increase markedly with age. It has been shown that elderly patients with self-reported osteoarthritis visit doctors twice as frequently as their unaffected peers. Such patients also experience more days of restricted activity and bed confinement compared to others in their age group. (Cartilage, 2010)
Cartilage has limited repair capabilities, because chondrocytes are bound in lacunae, they cannot migrate to damaged areas. Therefore, if damaged, cartilage is difficult to heal. Also, because hyaline cartilage does not have a blood supply, the deposition of new cartilaginous matrix is slow. Damaged hyaline cartilage is usually replaced by fibrocartilage scar tissue. (Cartilage, 2010)
Acetaminophen/paracetamol is generally used as a first line treatment and anti-inflammatory drugs (NSAIDs) are only recommended as add on therapy if pain relief is not sufficient. This is due to greater safety of acetaminophen as opposed to NSAIDS. In addition, to these treatments, several cartilage regeneration techniques have been developed. These techniques include the following: (1) debridement or abrasion—surgeon arthroscopically removes loose cartilage which causes bleeding at the bone surface and growth of fibrocartilage (fibrous cartilage or scar tissue) but the fibrocartilage may not be strong enough; (2) microfracture—surgeon arthroscopically clears the affected area and makes several perforations in the bone to stimulate bleeding and growth of fibrocartilage; (3) mosaicpiasty or osteochondral autograft transplantation surgery—surgeon removes a plug of bone with cartilage covering from a healthy area of the joint and transplants it to the damaged area; (4) periosteal flap—surgeon removes a portion of the periosteum (connective tissue covering all bones) from shin and transplants it to the area of cartilage damage; (5) autologous chondrocyte implantation—surgeon arthroscopically removes small portion of cartilage from knee; tissue is sent to a lab to be cultured; second surgery required so lab-grown cells can be implanted at the site of the damaged cartilage; and (6) osteochondral allografts—donor bone is used to repair the damaged cartilage. These procedures yield mixed and often inconsistent results. There are still many questions that plague attempts at cartilage regeneration. There is a need to find definitive answers and to develop procedures that relieve arthritis symptoms and produce a durable replacement for damaged cartilage.
Bone
Bones are rigid organs that form part of the endoskeleton of vertebrates. Bones function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue. Bones comprise an organic component of cells and matrix as well as an inorganic or mineral component. Because bones come in a variety of shapes and have a complex internal and external structure they are lightweight, yet strong and hard, in addition to fulfilling their many other functions. One of the types of tissue that makes up bone is the mineralized osseous tissue, also called bone tissue, which gives it rigidity and a honeycomb-like three-dimensional internal structure. Other types of tissue found in bones include marrow, endosteum and periosteum, nerves, blood vessels and cartilage. (Bone, 2010)
There are several types of cells constituting the bone. For example, osteoblasts are mononucleate bone-forming cells that descend from osteoprogenitor cells. They are located on the surface of osteoid seams and make a protein mixture known as osteoid, which mineralizes to become bone. Osteoid is primarily composed of Type I collagen. Osteoblasts also manufacture hormones, such as prostaglandins, to act on the bone itself. They robustly produce alkaline phosphatase, an enzyme that has a role in the mineralization of bone, as well as many matrix proteins. Osteoblasts are the immature bone cells. In addition, bone lining cells are essentially inactive osteoblasts. They cover all of the available bone surface and function as a barrier for certain ions. Still further, osteocytes originate from osteoblasts that have migrated into and become trapped and surrounded by bone matrix that they themselves produce. The spaces they occupy are known as lacunae. Osteocytes have many processes that reach out to meet osteoblasts and other osteocytes probably for the purposes of communication. Their functions include to varying degrees: formation of bone, matrix maintenance and calcium homeostasis. They have also been shown to act as mechano-sensory receptors—regulating the bone's response to stress and mechanical load. They are mature bone cells. Finally, osteoclasts, a form of macrophage, are the cells responsible for bone resorption (remodeling of bone to reduce its volume). Osteoclasts are large, multinucleated cells located on bone surfaces in what are called Howship's lacunae or resorption pits. These lacunae, or resorption pits, are left behind after the breakdown of the bone surface. Because the osteoclasts are derived from a monocyte stem-cell lineage, they are equipped with phagocytic like mechanisms similar to circulating macrophages. Osteoclasts mature, migrate, or both to discrete bone surfaces. Upon arrival, active enzymes, such as tartrate resistant acid phosphatase, are secreted against the mineral substrate. (Bone, 2010)
In the disease commonly known as osteoporosis, bone demineralizes and becomes abnormally rarefied. The cells and matrix of a bone comprise a framework of collagenous fibers which is impregnated with the mineral component of calcium phosphate (˜85%) and calcium carbonate (˜10%) which imparts rigidity to the bone. While osteoporosis is generally thought of as afflicting the elderly, certain types of osteoporosis may affect persons of all ages whose bones are not subject to functional stress. In such cases, patients may experience a significant loss of cortical and cancellous or trabecular bone during prolonged periods of immobilization. Elderly patients are known to experience bone loss due to disuse when immobilized after fracture of a bone, which may ultimately lead to a secondary fracture in an already osteoporotic skeleton. Diminished bone density may lead to vertebrae collapse, fractures of hips, lower arms, wrists, ankles as well as incapacitating pains.
Current therapies comprise invasive procedures (e.g. surgery or drug administration) as opposed to the described innovation which is a non-invasive procedure. Alternative nonsurgical therapies for such diseases include electrical bone growth stimulation comprised of electric and magnetic field therapies. However these therapies are moderately invasive as they rely on either skin contact or insertion of probes/electrodes into the tissue to achieve the desired results.
Nucleus Pulposus
Nucleus pulposus is the jelly-like substance in the middle of the spinal disc. It functions to distribute hydraulic pressure in all directions within each disc under compressive loads. The nucleus pulposus comprises disc chondrocytes (as opposed to articular chondrocytes), collagen fibrils, and proteoglycan aggrecans that have hyaluronic long chains which attract water. Attached to each hyaluronic chain are side chains of chondroitin sulfate and keratan sulfate. (Nucleus pulposus, 2008)
Electric and Magnetic Fields
An electric field is a property that describes the space that surrounds electrically charged particles. Electric fields are created by differences in electric potential or voltage: i.e., the higher the voltage, the stronger will be the resultant electric field. In contrast, magnetic fields that are generated electromagnetically are created when electric current flows: i.e., the greater the current, the stronger the magnetic field. An electric field will exist even when there is no current flowing. In contrast, a magnetic field generated electromagnetically will not exist when there is no current. If current does flow, the strength of the magnetic field that is generated electromagnetically will vary with power consumption but the electric field strength will be constant. Resultant forces are related to both electric and magnetic fields. The force associated with an electric field depends on a stationary or static charge. Conversely, the force exerted on a charged particle associated with a magnetic field (i.e., Lorentz force) depends on a moving charge. Further, electric and magnetic fields are not entirely mutually exclusive. For example, charged particles do not only produce electric fields. As charges move, they generate magnetic fields, and if the magnetic field changes, the change in said magnetic field will generate electric fields. Thus weak metals (ions) such as CA2+, K+, Li+, and Mg2+ are all subject to modulation or resonance effect and can be made to move sub-cellularly due to magnetic flux. Stated differently, a changing magnetic field gives rise to an electric field. In nature lightning is an example of an atmospheric electrical discharge that creates an attendant magnetic field.
Electrical Stimulation Therapies
Electrical stimulation therapies include: capacitive coupling (CC); and direct current (DC) or direct coupling. The original basis for forms of electric stimulation therapy was the observation that physical stress on bone causes the appearance of tiny electric currents (i.e., a piezo-electric effect) that, along with mechanical strain, were thought to be the mechanisms underlying transduction of the physical stresses (compression and tension) into an electrical signal that promotes bone formation. CC relies on an electric field that is generally generated by 2 capacitive plates or electrodes placed on a patient's skin on opposite ends of a region of interest to apply electrical stimulation in the region of interest. DC-based therapies require the placement of opposing electrodes in direct contact with the skin surface surrounding the tissue of interest (Trock, 2000) and generally involve implantation of the electrodes. The region of interest is stimulated by a constant direct current.
Magnetic Field Therapies
Magnetic field therapies include: time-varying magnetic field (TVMF) therapies including pulsed electromagnetic field (PEMF) therapies. The general use of time-varying magnetic fields to stimulate the growth of cells has been previously disclosed in the related art. It has been theorized that the piezo-electric properties in human tissue such as bone and cartilage forms the basis for regulating bone and cartilage formation. Specifically, because a magnetic field imposes a force on magnetic particles and moving electrically charged particles, the magnetic field forces simulate physical stress in human tissue thereby resulting in small, induced currents (Faraday currents) in the tissue's highly conductive extracellular fluid. In general, time-varying magnetic field therapies involve the use of coils to electrically generate a magnetic field. PEMFs are considered a subset of time-varying magnetic field therapies and are generally associated with pulses or bursts in its waveforms. Resultant waveforms used in PEMF therapies can be substantially monophasic, substantially biphasic, substantially square, sinusoidal, or substantially triangular. Further, PEMF therapies are generally comprised of frequencies on the lower end of the electromagnetic spectrum such as from 6-500 Hz. Further, waveforms used in PEMF therapies generally have high rising and falling slew rates on the order of Tesla/sec, thereby promoting said pulses or bursts.
In U.S. Pat. No. 7,179,217 an apparatus for enhancing tissue repair in mammals is disclosed. The disclosed apparatus comprises: a sleeve for encircling a portion of a mammalian body part, said sleeve comprising an electrically conductive coil capable of generating a magnetic field when an electrical current is applied thereto, means for supporting the sleeve on the mammalian body part; and a means for supplying the electrically conductive coil with a square wave time-varying electrical current sufficient to create a time-varying magnetic force of from approximately 0.05 G to 0.5 G within the interior of the coil in order that when the sleeve is placed on a mammalian body part and the time-varying magnetic force of from approximately 0.05 G to 0.5 G is generated on the mammalian body part for an extended period of time, tissue regeneration within the mammalian body part is increased to a rate in excess of the normal tissue regeneration rate that would occur without application of the time-varying magnetic force. The electrically conductive coil is preferably a ferromagnetic material, such as wire, with approximately ten windings per inch. The sleeve can be placed on a body part, e.g. an arm or a leg, of the mammal and the body part exposed to the 0.05 G to 0.5 G time-varying magnetic force for an extended period of time to enhance tissue repair, such increasing the healing rate of bone fracture repair or increased healing rate of ulcerated skin. It is preferable that the treated mammal is provided an increased level of calcium ions (Ca+ or Ca++) during the application of the time-varying magnetic force.
Anabolic and Catabolic Gene Expressions
Scientists have traditionally classified hormones into two categories: anabolic or catabolic, depending on which part of metabolism they stimulate. The traditional anabolic hormones are the anabolic steroids, which stimulate protein synthesis and muscle growth. Conversely, the traditional catabolic hormones are adrenaline (and other catecholamines). In recent decades, many more hormones with at least some effects have been discovered, including cytokines or paracrine and autocrine factors which are the products of genomic up or down regulations. The combination of anabolic and catabolic effects is by no means the sum and total of the genomic capacity to stimulate reconstructive changes within the physiology. Further specific genes and some molecules work in concert with each other or in gene cascades (chaperones) which facilitate the end goal of tissue remodeling, with processes such as glucose metabolism fluctuating to match an animal's normal periods of activity throughout the day (Ramsey, Marcheva, Kohsaka, & Bass, 2007).
Similarly, known biomolecules such as vitamins are extremely useful in perpetuating the process of normal cartilage and bone maintenance. Two such molecules are Vitamin (specifically D3) and Vitamin K. The actions of these vitamins are known to a degree in relation to normal mammalian (specifically human) physiology (Ishikawa, 2006), (Atkins, 2009), (Koshihara, 1997). The inventors postulate that due to the facilitated stimulation of important gene expressions (specifically osteocalcin up-regulation which was unanticipated as part of the responding cascade) that addition of increased concentrations of these two vitamins during treatment of the affected area (ROI) in any outlined regime or matrix will further enhance and accelerate the formation of new bone and differentiate the expression of bone from cartilage in the subject tissue as mineralization will produce bone and not cartilage. Osteocalcin is known to be a biological cofactor which when exposed to increased amounts of Vitamin K leads to mineralization of new bone. Thus, addition of Vitamin D3 in concentrations from 200-1000 IU daily and Vitamin K from about 50 to about 2000 mg daily will further facilitate the regeneration (anabolic effects) of bone and differentiate bone from cartilage formation. Additionally, osteocalcin is also tied to energy generation (needed especially for rapid cell growth) by modulating the production of insulin.
Anabolism is the set of metabolic pathways or genomic and protein responses that construct molecules from smaller units (de Bolster, 1997). These reactions require an energy system which in the case of cells is derived from other genomic responses in the breakdown of energy “packets” in the cell. One way of categorizing metabolic processes, whether at the cellular, organ or organism level is as anabolic or as catabolic, which is the opposite of anabolic. Anabolism is powered by catabolism, where large molecules are broken down into smaller parts and then used up in oxidative metabolism of respiration. Many if not all anabolic processes are powered by adenosine triphosphate (ATP), adenosine diphosphate (ADP) or adenosine monophosphate (AMP) (Nicholls & Ferguson, 2002). Anabolic processes are generally associated with “building up” or regeneration of organs and tissues. These processes produce growth and differentiation of cells and increase in organ or body size, a process that involves manufacture and production of complex building blocks known as molecules. Classic examples of anabolic processes include the regeneration, growth of cartilage, growth and mineralization of bone and increases in muscle mass and complexity. In genomic terms and for the purposes herein, “anabolic” will be associated with the building of tissue or the regeneration of tissue from an organic perspective.
Catabolism is the set of pathways that break down molecules into smaller units and release energy (de Bolster, 1997). In catabolism, large molecules such as nucleic acids, proteins, polysaccharides, and lipids, and are broken down into smaller units such as amino acids, nucleotides, monosaccharides, and fatty acids, respectively. As molecules such as polysaccharides, proteins, and nucleic acids are made from long chains of these small monomer units, the large molecules are called polymers. Cells use the monomers released from breaking down polymers to either construct new polymer molecules, or degrade the monomers further to simple waste products, releasing energy. Cellular wastes include lactic acid, acetic acid, carbon dioxide, ammonia, and urea which require scavenger molecules to “clean up” so as not to pollute the organic system. Creation of these wastes is a function of the oxidation process involving a release of chemical energy, some of which is lost as heat, but the rest of which is used to drive the synthesis of adenosine triphosphate (ATP). This molecule acts as a way for the cell and thus the organism to transfer the energy released by catabolism to the energy-requiring reactions (genomic functions) that make up anabolism or construction of the tissue. These anabolic processes are controlled by genomic cascades which “cooperate” to achieve the desired end result; that of formation of new tissue. This catabolism provides the chemical energy and genomic instruction necessary for the maintenance and growth of cells, which can be referred to as a reparative function. In genomic terms, catabolism is the reorganization or destruction of tissue such as one sees in osteoarthritis or osteoporosis. Thus the process of bone remodeling and osteoclastogenesis are examples of a catabolic event driven by genes specifically associated with the process. For the purposes of herein, “catabolic” will be associated with a reparative function and specifically, the breakdown, reorganization, or the degeneration of tissue from an organic perspective.
Currently, full advantage is not being taken of the use of these biophysical and electrical stimuli in the health care professions, due to lack of knowledge and education in this field. However, as the underlying mechanisms at the molecular and cellular level become understood, it is hoped that these stimuli will be better defined and utilized, and as a result, medical instrumentation using this medical technology will therefore become more widely implemented in the clinical and out-patient setting. Currently, the related art primarily depends on frequency and B-Field magnitude associated with an electromagnetic field waveform for the stimulated growth of biological cells and associated tissue. In fact, related art publications indicate that a B-Field magnitude is the primary control variable for affecting biological cell and tissue growth. At some point, the B-field magnitude's effect becomes more of a thermal effect as compared to a physical force imparted at the cellular level. For example any magnetic field greater than 30 kHz falls into the radio frequency range and is known to result in thermal heating effects at the sub-cellular level. The related art is deficient in discovery of a specific stimulation field profile necessary for up-regulating and down-regulating specific genes, wherein said profile is comprised of not only frequency and B-Field magnitude, but also waveform shape, rise time, rising slew rate, fall time, falling slew rate, duty cycle, dwell time, time of exposure, and other possible factors. The therapeutic implications of the discovery of specific profiles associated with stimulating specific genes will be explained herein. Thus, it would be desirable to provide an apparatus and method of use which would promote the stimulation of specific genes by a specific stimulation field of predetermined profile.